The present disclosure relates to a display device that enables viewing of a video and a control method of the display device.
Generally, two videos constituted from a video for a right eye and a video for a left eye are necessary for viewing a stereoscopic video. Among methods of presenting a stereoscopic image, there is proposed a method of using polarization glasses or a method of using a parallax barrier or a lenticular lens without using the glasses, for example. In the former method, view images (or disparity images) are seen using the glasses, based on polarization states that are mutually different between the right and left eyes. In the latter method, prescribed view images among a plurality of view images are guided to a viewer using the parallax barrier or the lenticular lens. A stereoscopic display device using the parallax barrier is so configured that videos formed by light rays which have passed through apertures (transmissive units) of the parallax barrier are different view images for the right and left eyes.
While an autostereoscopic display device has an advantage that stereoscopic viewing is possible without using special glasses, it has the following issue. As mentioned above, view images (views 1, 2, 3, 4, 1, 2, 3, 4, . . . in FIG. 1) are periodically arranged in pixels on a liquid crystal display. For this reason, at the boundary of the respective periods, or the border of the period of four video data (the view 4 and the view 1), a pseudoscopic zone is present. In the pseudoscopic zone, a view video to be entered into a right eye is guided to a left eye, and a view video to be entered into the right eye is guided into the left eye. In the pseudoscopic zone, a pseudoscopic phenomenon occurs. That is, a viewer perceives a stereoscopic video image of which the front and the back are inverted or sees unnaturally blending of the front and the back of the stereoscopic video image. This phenomenon gives an unnatural feeling to the viewer.
There has been proposed an attempt to remove discomfort of a viewer against pseudoscopy as much as possible (refer to JP 2000-47139A, for example). In the method in JP 2000-47139A, the position of a viewer is detected, and a pattern shape of a mask pattern of an optical modulator corresponding to the parallax barrier is changed based on information on the position, thereby reducing the discomfort of the viewer against the pseudoscopy.